1. Field of the Invention
The present invention pertains to a removable valve and conduit assembly for use in extracting excess lubricant from a sump formed in an accumulator, compressor or other vessel in a vapor compression refrigeration system.
2. Background
In vapor compression refrigeration systems compressor lubricant is sometimes circulated through the refrigerant flow circuit to assure that certain working parts of the compressor are adequately lubricated during operation thereof. More often, the lubricant is unavoidably introduced into the refrigerant flow circuit from the cylinder walls of reciprocating piston type compressors, for example. Moreover, in certain instances a tracer liquid is injected into the refrigerant flow circuit for detection of leaks in the system. However, it is not unusual to overcharge a system with compressor lubricant or with a tracer liquid which can interfere with the efficient operation of vapor compression refrigeration systems and in extreme cases result in severe damage to the compressor due to ingestion of excessive amounts of liquid into the compression chambers.
Although it is possible to provide a drain cock in the refrigerant flow circuit at some point, many systems do not have a convenient point for locating such a device, and it is considered undesirable to leave an easily openable valve in the system whereby such a valve may be inadvertently opened resulting in loss of refrigerant fluid. Accordingly, there has been a need for an arrangement in a vapor compression refrigeration system wherein a sump is provided at a preferred location in the refrigerant flow circuit and wherein excessive amounts of liquid, usually compressor lubricant, may be extracted from the system at this sump by the insertion of a liquid extraction device which may be temporarily connected to the system. Such an extraction device is preferably connected to an accumulator vessel having a sump located such that the device will extract substantially all liquid which has collected in the accumulator sump. These desiderata have been accomplished with the refrigeration system and device in accordance with the present invention.